- Mac OS X Public Beta (2000)
- SUSE Linux 7.0 (2000)
- Debian 2.2 (2000)
- OpenBSD 2.7 (2000)
- Solaris 8 (2000)
- AmigaOS 3.9 (2000)
- and so on... [0]
Hardly “no alternatives” in my humble opinion.
And in office space, MS-DOS was still a thing for quite some time.
[0]: https://en.wikipedia.org/wiki/Timeline_of_operating_systems#...
Firefox worked, as did Flash (hello NewGrounds!), Java (RuneScape), you could do a ton and be nigh invulnerable to all the malware on the internet of the early 2000s.
It's interesting to think that the project has survived for so long, even if nowadays the Libre office variety is more widely used.
The 2001 decision was comparing desktop options at a time when they weren't any. Today's mobile users have plenty of options, plenty of brands and OSs to choose from.
Android is Linux under the hood. It just doesn't use any of the cruft that desktop Linux usually has, like Xorg.